The present invention relates to the casting of iron pipe in a centrifugal casting machine. More specifically, this invention relates to the computer control of the process, in which a pouring ladle is automatically filled with an amount of molten iron, from a backup ladle, that is required to cast a particular size pipe.
The centrifugal casting of iron is accomplished by the use of a centrifugal casting machine. The machine comprises a rotating mold that is rollable toward and away from an iron trough which is adapted to be inserted into the rotating mold. Molten iron is poured from a pouring ladle into the iron trough and pours out of the end of the trough into the rotating mold. The end of the pipe first formed is the bell end which has core therein to insure the accurate forming of the bell end of the pipe. However, the core does not extend past the bell end into the length of the pipe. The movement of the casting machine is accomplished by either a hydraulic cylinder, a hydraulic or electrical motor, or a combination of these devices. It is to be understood that in certain casting machines, the casting machine itself remains stationary, and the iron trough is moved away from the casting machine. The principles of the present invention are equally applicable to such an arrangement.
A problem in this centrifugal casting of iron pipe is the supplying of molten iron from the backup ladle to the pouring ladle, with each casting machine each having its own pouring ladle and backup ladle. The amount of the molten iron supplied from the backup ladle into the pouring ladle was manually controlled by an operator. This led to the potential for either too little or to much molten iron entering the pouring ladle and affecting the casting of the iron pipe. Accordingly, it is an object of the present invention to provide a method of automatically controlling the amount of molten iron provided from the backup ladle to the pouring ladle.
It is another object of the present invention to provide a method of automatically controlling the amount of molten iron provided from the backup ladle to the pouring ladle in relation to the size of iron pipe being cast.